Recently, as a headlight for vehicles, there is an illumination device 100 that uses a light-emitting diode (LED) (Patent Literature 1).
FIG. 21 is a cross-section view of the above-mentioned conventional illumination device 100. It includes a LED light source 10 of the illumination device 100, a substrate 11, a reflection plate 12, and an opening 13. The light emitted from the LED light source 10 is reflected by the reflection plate 12, and is emitted forward through the opening 13.
The LED light source 10 is a high output LED, and is a point light source. A shape of the reflection plate 12 is determined based on the optical design with respect to the point light source. Since the LED light source 10 is a high output LED, it generates a high amount of heat. Therefore, a cooling mechanism is provided on or under the substrate 11 (not shown in the figure).